1. Field of the Invention
The present disclosure relates to a circuit breaker having an insulating cover.
2. Background of the Invention
In general, a circuit breaker refers to a device for opening and closing a load device or interrupting a current in the event of an accident such as earthing, short-circuit, or the like, in a transmission & sub-station system or an electrical circuit. Also, a circuit breaker, in which a circuit breaking part is insulated by an insulator and assembled, may generally manually open or close a line in use or may open or close it from a remote area through an electrical manipulator, or the like, outside a metal container. Also, in the event of overload or short-circuit, the circuit breaker automatically cuts off the line to protect an electric power system and a load device.
A circuit breaker may be classified into an air operation method, a hydraulic operating method, a spring operation method, and the like according to the way in which a circuit breaking part is operated. A circuit breaker may also be classified into an air circuit breaker (ACB) that extinguishes arc by blowing air, a gas circuit breaker (GCB) that extinguishes arc by blowing gas, and the like, according to the way in which arc generated when a mover is separated from a stator by manipulating a circuit breaking part is extinguished.
In order to cut off an electric circuit as mentioned above, a stator and a mover are installed in a circuit breaking part of a circuit breaker. The stator and the mover are usually in contact to allow a current to flow therethrough, and when a large current flows due to a fault generated in somewhere of the line, the mover is rapidly separated from the stator to interrupt current.
In the related art circuit breaker, when an overcurrent or a fault current occurs, an operating part rotates a mover to separate it from a stator. The operating part also includes a shaft assembly made of a metal. The shaft assembly is connected to the mover through a link structure. A housing accommodating the mover, or the like, has a hole in which the link structure is inserted and operated.
When the mover is separated from the stator, a high temperature high pressure arc is generated from a contact between the mover and the stator, and due to the high temperature high pressure arc, a metal component such as the shaft assembly, or the like, may be melted and leaked to the outside through the hole formed in the housing. In this case, phase-to-phase insulation may be weakened by the molten metal residue.
Meanwhile, when the shaft assembly of the related art breaker is made of plastic, a size of the circuit breaker may be increased.